The overall objective of this research proposal is to study the identity and immunochemical properties of bacteria substances as well as the substances in the host secretions that are involved in the binding of pyogenic organisms to oral mucosal cells. We intend to utilize in vitro systems, consisting of isolated oral epithelial cells, pyogenic bacteria and various agents derived from both the host and bacteria. Most of our studies will be performed with oral mucosal cells and secretions from healthy adult laboratory personnel. Some experiments will be conducted using oral mucosal cells from newborn infants. In some cases serum samples will be obtained from patients with various infectious diseases to determine their affect on the binding of pyogenic bacteria to mucosal surface.